JP5863386B2 - Magnetic field generator - Google Patents

Description

  The present invention relates to a magnetic field generator for a magnetron sputtering apparatus.

  As a sputtering device used to form a thin film on the surface of a substrate, a magnetic circuit is provided on the surface side of the target using a magnetic circuit provided on the back surface of the target, and the plasma density is increased by this magnetic field to increase the film formation efficiency. A so-called magnetron sputtering apparatus is widely used.

  By the way, in this magnetron sputtering apparatus, the target is not sputtered evenly, and a part of the target is sputtered in a concentrated manner (the erosion region is narrow), so that a relatively large amount of target material remains in a region that is difficult to be sputtered. There is a problem that the target life is exhausted. For example, as disclosed in Patent Document 1, the target life is extended by setting the arrangement of permanent magnets constituting the magnetic circuit so as to sputter the target as evenly as possible. The current situation is to make it easier.

JP 2009-57622 A

  The present invention has been made in view of the current situation as described above, and is intended to further extend the life of the target. The sputtered area (erosion area) of the target is enlarged, and the target can be sputtered more evenly. An object of the present invention is to provide a magnetic field generator with extremely excellent practicality, such as facilitating the arrangement of a magnetic plate for correcting the magnetic field distribution when adjusting the film thickness distribution.

  The gist of the present invention will be described with reference to the accompanying drawings.

In a magnetic field generator for a magnetron sputtering apparatus comprising a magnetic circuit for generating a magnetic field and a target support for supporting a target disposed in close proximity to the magnetic circuit, the magnetic circuit is bonded to the bottom yoke 1 and is a target. An inner permanent magnet 2 having a magnetization direction along a direction orthogonal to the surface, and an outer side bonded to the bottom yoke 1 so as to surround the inner permanent magnet 2 and having a magnetization direction opposite to the inner permanent magnet 2 The permanent magnet 3 forms a zero point crossing region where the vertical component of the magnetic flux density on the target surface intersects the zero point three times, or a zero peripheral region where the vertical component of the magnetic flux density is flat at the zero point is formed. The auxiliary permanent magnet is bonded to the bottom yoke 1 so that the auxiliary permanent magnet is adjacent to the inner permanent magnet 2. Adhering to the bottom yoke 1 and adhering to the bottom yoke 1 so as to be adjacent to the first auxiliary permanent magnet 4 having a magnetization direction opposite to the inner permanent magnet 2 and the outer permanent magnet 3, The second auxiliary permanent magnet 5 having a magnetization direction opposite to that of the outer permanent magnet 3 is bonded to the bottom yoke 1 between the first auxiliary permanent magnet 4 and the second auxiliary permanent magnet 5. Magnetization is performed so that the perpendicular component of the magnetic flux density of the magnetic circuit forms a zero-point crossing region where the zero point intersects the zero point three times, or a zero peripheral region where the perpendicular component of the magnetic flux density is flat at the zero point is formed. Ri consists third auxiliary permanent magnets 6 that direction is set, the distal end of the inner permanent magnet 2 and the first auxiliary permanent magnet 4 or the outer permanent magnet 3 and the second auxiliary permanent magnet 5 The magnetic plate 7 is placed This is intended according to the magnetic field generator, characterized in that the magnetic plate 7 set the zero peripheral region in the range of -30 [G] or +30 [G] below.

  Further, the front end portions of the inner permanent magnet 2 and the first auxiliary permanent magnet 4 adjacent to the inner permanent magnet 2 are set at the same height so that the magnetic plate 7 can be placed on the front end portion. The magnetic field generator according to claim 1, wherein the magnetic field generator is provided.

  Further, the outer permanent magnet 3 and the tip of the second auxiliary permanent magnet 5 adjacent to the outer permanent magnet 3 are set at the same height so that the magnetic plate 7 can be placed on the tip. It concerns on the magnetic field generator of any one of Claim 1, 2 characterized by the above-mentioned.

Further, the inner permanent magnet 2, the outer permanent magnet 3, the first auxiliary permanent magnet 4, the second auxiliary permanent magnet 5, and the third auxiliary permanent magnet 6 are made of Nd-Fe-B magnets. It is comprised, It concerns on the magnetic field generator of any one of Claims 1-3 characterized by the above-mentioned.

Further, the shape of the magnetic plate 7 on which the unit sizes of the inner permanent magnet 2 and the first auxiliary permanent magnet 4 or the outer permanent magnet 3 and the second auxiliary permanent magnet 5 are placed at the tip of the permanent magnet. The magnetic field generator according to any one of claims 1 to 4 , wherein the magnetic field generator is set to have the same shape.

In addition, the inclinations of the magnetization directions of the inner permanent magnet 2, the first auxiliary permanent magnet 4, the outer permanent magnet 3, and the second auxiliary permanent magnet 5 each intersect with an adjacent permanent magnet at a predetermined angle. The auxiliary permanent magnets are arranged as described above, and the magnetic field generator according to any one of claims 1 to 5 is provided.

  Since the present invention is configured as described above, the erosion area of the target is expanded, the target can be sputtered more evenly, and the arrangement of the magnetic plate for correcting the magnetic field distribution can be easily performed. It becomes a magnetic field generator.

It is a structure schematic explanatory sectional drawing of a present Example. It is a structure schematic explanatory top view of a present Example. It is a schematic explanatory drawing of the attachment structure of a magnetic board. It is a schematic explanatory sectional drawing explaining the inclination of the magnetization direction of a permanent magnet.

  An embodiment of the present invention which is considered to be suitable will be briefly described with reference to the drawings showing the operation of the present invention.

  The magnetic field generated by the magnetic circuit forms a zero-point crossing region where the perpendicular component of the magnetic flux density on the target surface intersects the zero point three times, or forms a zero peripheral region where the perpendicular component of the magnetic flux density is flat at the zero point. To do.

  At this time, by using the first auxiliary permanent magnet 4 disposed adjacent to the inner permanent magnet 2 and the second auxiliary permanent magnet 5 disposed adjacent to the outer permanent magnet 3, the gradient of the magnetic flux density vertical component from directly above the magnet. In addition to these, by using the third auxiliary permanent magnet 6, it is possible to secure a wider zero-point crossing region or zero-peripheral region than the conventional technology (Patent Document 1). Therefore, the erosion region can be widened, and the material use efficiency can be improved accordingly.

  In addition, in order to form a more uniform magnetic field, it may be desired to weaken a part of the magnetic field strength using a magnetic plate. In this case, in order to weaken the magnetic field strength without greatly changing the characteristic shape of the magnetic flux density vertical component, it is necessary to attach a magnetic plate directly above the magnet. However, in the prior art (Patent Document 1), if the magnetic plate 30 is to be attached immediately above the magnet provided on the bottom yoke 33, the magnetic plate 30 is displaced between the N pole 31 and the S pole 32 where the magnetic flux density is concentrated. (See FIG. 3A). Therefore, in order to fix the magnetic plate 30, it is necessary to use an adhesive, and it takes much time for fixing.

  In this respect, in the present invention, since the N pole and the S pole are adjacent to each other (for example, the outer permanent magnet 3 and the second auxiliary permanent magnet 5, see FIG. 3B), the portions where the magnetic flux density is concentrated are adjacent. Since it becomes a boundary part between magnets and it becomes very difficult to shift, it is not necessary to use an adhesive for fixing the magnetic plate 7. Therefore, the time required for attaching the magnetic plate 7 can be greatly shortened, and a more uniform magnetic field can be easily formed.

  Further, for example, the magnetic plate 7 for placing the unit size of the inner permanent magnet 2 and the first auxiliary permanent magnet 4 or the outer permanent magnet 3 and the second auxiliary permanent magnet 5 on the tip of the permanent magnet. When the shape is set to the same shape as this, it becomes a guideline at which position the magnetic plate 7 is attached, and the time required for attaching the magnetic plate 7 can be further shortened.

  Specific embodiments of the present invention will be described with reference to the drawings.

  The present embodiment relates to a magnetic field generator for a magnetron sputtering apparatus including a magnetic circuit for generating a magnetic field and a target support that supports a target disposed in close proximity to the magnetic circuit. The magnetic circuit includes a bottom yoke. 1 and an inner permanent magnet 2 having a magnetization direction along a direction perpendicular to the target surface, and an inner permanent magnet 2 which is adhered to the bottom yoke 1 so as to surround the inner permanent magnet 2 and in a direction opposite to the inner permanent magnet 2 The outer permanent magnet 3 having a magnetization direction and a zero periphery where the perpendicular component of the magnetic flux density on the target surface intersects the zero point three times or the perpendicular component of the magnetic flux density is flat at the zero point An auxiliary permanent magnet bonded to the bottom yoke so that a region is formed, the auxiliary permanent magnet being adjacent to the inner permanent magnet 2 The first auxiliary permanent magnet 4 having a magnetization direction opposite to the inner permanent magnet 2 and the outer permanent magnet 3 are bonded to the bottom yoke 1. The bottom yoke 1 between the second auxiliary permanent magnet 5 having a magnetization direction opposite to that of the outer permanent magnet 3, and the first auxiliary permanent magnet 4 and the second auxiliary permanent magnet 5. To form a zero point crossing region where the vertical component of the magnetic flux density of the magnetic circuit crosses the zero point three times, or a zero peripheral region where the vertical component of the magnetic flux density is flat at the zero point Thus, the third auxiliary permanent magnet 6 whose magnetic field direction is set is formed.

  In this embodiment, each permanent magnet (each made of an Nd-Fe-B magnet) is provided upright on the horizontal plate-shaped bottom yoke 1 to form a magnetic circuit, and further on each permanent magnet (magnetic circuit). The upper plate is provided with a horizontal plate-like target support (not shown). A target is supported on the target support.

  In the present embodiment, each permanent magnet is formed in a frame-like body having a square shape in plan view. In this embodiment, assuming that the target has a target clamping groove in the center, the inner permanent magnet 2 is also provided with a space in the center of the magnetic circuit as a frame. When the target does not require a clamping groove, the inner permanent magnet 2 does not have to be a frame-like body, and may have another shape such as a rod shape (I shape).

  Each permanent magnet has an S pole on the top side of the outer permanent magnet 3, an S pole on the top side of the first auxiliary permanent magnet 4, and a second pole when the top side of the inner permanent magnet 2 is an N pole. The top surface side of the auxiliary permanent magnet 5 is an N pole (the reverse is also true). In addition, the third auxiliary permanent magnet 6 is appropriately set to the N pole or the S pole on the top surface side according to the magnetic field by other peripheral permanent magnets.

  In the magnetic circuit configured as described above, there is a central zero point of the vertical component of the magnetic flux density in the central line portion between the inner permanent magnet 2 and the outer permanent magnet 3. The zero point formed by the auxiliary permanent magnets on the left and right is configured so that there are at least two left and right one points. A zero peripheral region where the vertical component of the magnetic flux density is flat at the zero point is formed between the inner permanent magnet 2 and the outer permanent magnet 3 (that is, the vertical component of the magnetic flux density on the target surface is zero). The point is crossed three times, and a zero peripheral region is formed in which the vertical component of the magnetic flux density is flat at the zero point. Therefore, an erosion region is formed on the target along the zero peripheral region formed in a square shape in plan view.

  Furthermore, in the present embodiment, the magnetic plate 7 is placed on the tip of the permanent magnet, and the magnetic plate 7 sets the zero peripheral region to a range of −30 [G] to +30 [G]. Therefore, it is possible to form a uniform zero peripheral region.

  In general, if the magnetic field strength inside or outside the magnetic circuit is corrected, unevenness can be eliminated as much as possible. Therefore, at least the inner permanent magnet 2 and the first inner magnet 2 adjacent to the inner permanent magnet 2 are used. Either the tip of the auxiliary permanent magnet 4 (top surface), or the outer permanent magnet 3 and the tip of the second auxiliary permanent magnet 5 adjacent to the outer permanent magnet 3 (top surface), It is set to the same height so that the magnetic plate 7 can be placed at the tip.

  In this embodiment, the top surfaces of the permanent magnets are set to have the same height. This is because the target support is provided well and the magnetic body 7 is provided well.

  Moreover, the unit size of each permanent magnet (the inner permanent magnet 2 and the first auxiliary permanent magnet 4 or the outer permanent magnet 3 and the second auxiliary permanent magnet 5) constituting the magnetic circuit is set to the magnetic plate 7 to be placed. When the same planar view shape as the planar view shape is set, it becomes a guideline for determining the position to attach the magnetic plate 7 using the evaluation result of the film thickness distribution, and the time required for attaching the magnetic plate 7 is further shortened. be able to.

  In the present embodiment, the permanent magnets are arranged so that the inclinations of the magnetization directions of adjacent NS pairs of magnets intersect at a predetermined angle.

  That is, as illustrated in FIGS. 4A and 4B, the inclination of the magnetization direction of the inner permanent magnet 2 and the first auxiliary permanent magnet 4 (the outer permanent magnet 3 and the second auxiliary permanent magnet 5) is If they are arranged parallel to each other, the film thickness distribution will be uneven. In this respect, in the present embodiment, as shown in FIGS. 4 (c) and 4 (d), in order to avoid unevenness as much as possible, each slightly intersects at a predetermined angle (for example, several degrees). It arrange | positions adjusting the inclination of the magnetization direction of each permanent magnet. The arrows in FIG. 4 indicate the inclination of the magnetization direction of each permanent magnet (white and black are different polarities). 4A to 4D, the inclination of the third auxiliary permanent magnet 6 is 0 °.

  The inclination of the magnetization direction of the permanent magnet is such that, in the magnetic field molding process in the magnet manufacturing process, the magnetization easy axis of the pulverized magnet material (in the magnetic material, the specific crystal direction that is easily magnetized) is along the magnetic field direction. The inclination of the magnetization direction can be evaluated by measurement, but the inclination is 0 [deg. In order to configure a magnetic circuit by selecting magnet pieces close to], it is inevitable that the delivery time is increased and the cost is increased.

  In this regard, as described above, when the adjustment / arrangement is performed in consideration of the inclination of the magnetization direction of the permanent magnet, the magnetic circuit can be configured at a lower cost than the case where the magnetic circuit is configured by selecting the magnet pieces. It has been confirmed that unevenness in the zero peripheral region can be suppressed.

  Since the present embodiment is configured as described above, the magnetic field generated by the magnetic circuit is such that the vertical component of the magnetic flux density on the target surface intersects the zero point three times, and the vertical component of the magnetic flux density is flat at the zero point. Forming a zero peripheral region.

  At this time, by using the first auxiliary permanent magnet 4 disposed adjacent to the inner permanent magnet 2 and the second auxiliary permanent magnet 5 disposed adjacent to the outer permanent magnet 3, the gradient of the magnetic flux density vertical component from directly above the magnet. By using the third auxiliary permanent magnet 6 in addition to these, it becomes possible to secure a wider area around the zero than in the prior art (Patent Document 1), and thus erosion The area can be increased, and the material use efficiency can be improved accordingly.

  Further, since the auxiliary permanent magnets 4 and 5 are arranged as described above, the N pole and the S pole are adjacent to each other (for example, the outer permanent magnet 3 and the second auxiliary permanent magnet 5, see FIG. 3B). ), The portion where the magnetic flux density is concentrated becomes a boundary portion between adjacent magnets, and even if the magnetic plate 7 is arranged, it is hardly displaced, and it is not necessary to use an adhesive for fixing the magnetic plate 7. Therefore, the time required for attaching the magnetic plate 7 can be greatly shortened, and a more uniform magnetic field can be easily formed.

  In this case, by varying the thickness of the magnetic plate 7 to be attached, it is possible to correct the unevenness of the vertical magnetic field strength that occurs near the zero point of the magnetic flux density vertical component.

  Therefore, the present embodiment is extremely practical because the erosion region of the target is expanded, the target can be sputtered more evenly, and the magnetic plate for correcting the magnetic field distribution can be easily arranged.

  Note that the present invention is not limited to this embodiment, and the specific configuration of each component can be designed as appropriate.

DESCRIPTION OF SYMBOLS 1 Bottom yoke 2 Inner permanent magnet 3 Outer permanent magnet 4 First auxiliary permanent magnet 5 Second auxiliary permanent magnet 6 Third auxiliary permanent magnet 7 Magnetic plate

Claims (6)

In a magnetic field generator for a magnetron sputtering apparatus comprising a magnetic circuit for generating a magnetic field and a target support for supporting a target disposed in close proximity to the magnetic circuit, the magnetic circuit is bonded to a bottom yoke and is attached to a target surface An inner permanent magnet having a magnetization direction along a direction perpendicular to the inner permanent magnet, an outer permanent magnet adhered to the bottom yoke so as to surround the inner permanent magnet, and having a magnetization direction opposite to the inner permanent magnet, and a target The bottom yoke is formed such that the vertical component of the magnetic flux density on the surface forms a zero point crossing region where the zero point intersects the zero point three times, or a zero peripheral region where the vertical component of the magnetic flux density is flat at the zero point is formed. An auxiliary permanent magnet to be bonded,
The auxiliary permanent magnet is bonded to the bottom yoke so as to be adjacent to the inner permanent magnet, and has a first auxiliary permanent magnet having a magnetization direction opposite to the inner permanent magnet;
A second auxiliary permanent magnet bonded to the bottom yoke adjacent to the outer permanent magnet and having a magnetization direction opposite to the outer permanent magnet;
Bonded to the bottom yoke between the first auxiliary permanent magnet and the second auxiliary permanent magnet to form a zero point crossing region where the vertical component of the magnetic flux density of the magnetic circuit crosses the zero point three times. to or Ri consists a third auxiliary permanent magnets whose magnetization direction is set to zero peripheral region vertical component of the magnetic flux density is flat at zero point is formed,
A magnetic plate is placed at the tip of the inner permanent magnet and the first auxiliary permanent magnet or the outer permanent magnet and the second auxiliary permanent magnet, and this magnetic plate defines the zero peripheral region at −30 [G ] A magnetic field generator characterized by being set in a range of not less than +30 [G] .   The tip of the inner permanent magnet and the first auxiliary permanent magnet adjacent to the inner permanent magnet are set at the same height so that a magnetic plate can be placed on the tip. The magnetic field generator described in 1.   2. The front end of the outer permanent magnet and the second auxiliary permanent magnet adjacent to the outer permanent magnet are set at the same height so that a magnetic plate can be placed on the front end. 3. A magnetic field generator according to claim 1. The inner permanent magnet, the outer permanent magnet, the first auxiliary permanent magnet, the second auxiliary permanent magnet, and the third auxiliary permanent magnet are composed of Nd—Fe—B based magnets. The magnetic field generator according to any one of claims 1 to 3 . The unit size of the inner permanent magnet and the first auxiliary permanent magnet or the outer permanent magnet and the second auxiliary permanent magnet is set to the same shape as the shape of the magnetic plate placed on the tip of the permanent magnet. The magnetic field generator according to any one of claims 1 to 4 . The auxiliary permanent magnets are arranged such that inclinations of magnetization directions of the inner permanent magnet, the first auxiliary permanent magnet, the outer permanent magnet, and the second auxiliary permanent magnet intersect with adjacent permanent magnets at a predetermined angle, respectively. A magnetic field generator according to any one of claims 1 to 5 , wherein a magnet is arranged.

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